Monday, 14 October 2013

All you ever wanted to know about intelligence (but were too bright to ask) Part 1

There is a recently published Primer in Current Biology on Intelligence written by Ian Deary, which is hidden behind a paywall, lest it be read by anybody other than a fully paid up current biologist. Strange world, the one in which scholars write things for nothing in order that other citizens should have to pay for the privilege of reading them. Such payments made some sense when publishing required printing, but rather less now, when the transmission of bytes is close to free.

I will be using the article as a framework for a series of posts, taking one theme at a time, picking out some highlights and adding some extra bits. My target audience is bright people who don’t believe in intelligence. For a variety of reasons, they think it unseemly to acknowledge that they can think faster than others. This is not altogether stupid, because in many genocides it is the intelligent who get slaughtered. Excessive modesty may have some survival value.

“Some people are cleverer than others. It is a prominent and consistent way in which people differ from each other; the measurements we make of people’s cleverness produce scores that are correlated with important life outcomes; it is interesting to discover the mechanisms that produce these individual differences; and understanding these mechanisms might help to ameliorate those states in which cognitive function is low or declining.”

Deary distinguishes between cognitive psychologists who are trying to find out how the mind works and differential psychologists who mostly focus on how people differ in the workings of their minds. The latter try to show precisely the ways in which people differ, and try to discover the causes of those differences. The two tribes don’t communicate very well. Cognitive psychologists, in my view, are missing a trick. A very brief vocabulary and/or digit span test or, with more time, a group intelligence test, would give them important data, and help place their results in the context of human differences.

Deary identifies four major sources of scepticism about intelligence:

1 The concept appears to be too general. People argue that they are better at some skills than others, and assume different modules are involved, such that we are all good at some specific mental skill.

2 Historical events in intelligence research which are discreditable. In the UK, the 11+ missed out people who later showed demonstrable talent; cases of probable fraud in reporting results; over use and over-interpretation of intelligence tests; controversies about intelligence differences between ethnic groups; or claims that “ordinary” intelligence has now been replaced by tests of “multiple” intelligence.

3 “It is possible that clever people develop a kind of cognitive noblesse oblige; they kind of know they have won the lottery on a valuable trait, but they think it is bad form to acknowledge it.”

4 They probably haven’t read good quality research on the topic.

I find that most of the hostility about intelligence comes from bright people, who keep up with the broad sweep of newspaper reports and popular books, but have not looked at good quality research. Despite this lack they are surprisingly vehement when they ridicule IQ.

So, it would appear that intelligence is most disparaged by the intelligent. “Define intelligence” they demand, with a knowing smile. Personally, I have found that the only answer is to show them a photo of George W. Bush. (But I am getting ahead of myself). There are three types of answer: a quip, an explanation, and a formula.

The Quip: “Intelligence is what you need when you don’t know what to do”. Carl Bereiter coined this elegant phrase. It captures the ultimate purpose of intelligence, which is to help you cope with the unknown. The best intelligence test is the puzzle to which no one knows the answer. For example, is there a detectable particle which gives objects mass?

The Explanation: “Intelligence is a very general mental capability that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings — ‘catching on,’ ‘making sense’ of things, or ‘figuring out’ what to do.” Linda Gottfredson and 52 leading psychometricians agree with this explanation. http://www.udel.edu/educ/gottfredson/reprints/1997mainstream.pdf

The formula: g+group+specific skill+error, where g accounts for about 50% of the variance. (I have written this in English, but it should be displayed in eigenvalues).

So, let us look behind the formula (in English) “In 1904 Spearman found that people who perform well on one type of cognitive test tend to perform well on others. That is, if cognitive test scores are ordered so that better performance equals a higher score, the correlations between them are all positive. There is shared variation among all types of cognitive performance. Spearman called this shared/common variance g: an abbreviation for general intelligence. In the 100+ years since then, every study that has applied a diverse battery of cognitive tests to a decent-sized group of people with a mix of ability levels has re-discovered the same thing: there is some cognitive variance shared by all cognitive tests. Typically, if one applies principal componentsanalysis, just under half of the total test score variance is accounted for by the first unrotated principal component.”

This finding of 50% of the variance in ability being due to g is matched by another finding: IQ-type test scores are highly reliable, and highly stable. For example, when the same intelligence test is taken at age 11 years and repeated at almost 80, about 50% of the variance is stable.

So, half of intelligence is due to a common factor, and half of the variance is stable throughout life.

Unfortunately, by this stage in the argument, we will have lost probably half of the intelligent readers. They are still smiling at the idea of anyone defining their intelligence. Can you please send them this link?

I think the purported criticisms are strawman versions of more substantive and hard to refute criticisms:

1 The concept appears to be too general. People argue that they are better at some skills than others, and assume different modules are involved, such that we are all good at some specific mental skill.

It is not necessary to assume we are all good at something to criticize the overall intelligence concept. Rather, it's enough to note that everyone has different relative strengths across their cognitive domains, and it's these variations, along with that 50% of ability that isn't "g-locked' and is somewhat variant, will often dominate the explanation.

To pull an economics concept into the discussion, intelligence by definition doesn't help one cope with something like Knightian uncertainty (an uncertainty that's simply not calculable in a meaningful way). More practically, how many philosophers does it take to screw in a light bulb? None, because it's not a problem that requires a philosopher. There are a lot of ways to resolve life's many uncertainties, and it's not always evident that throwing more intelligence at the problem is the most efficient.

2 Historical events in intelligence research which are discreditable. In the UK, the 11+ missed out people who later showed demonstrable talent; cases of probable fraud in reporting results; over use and over-interpretation of intelligence tests; controversies about intelligence differences between ethnic groups; or claims that “ordinary” intelligence has now been replaced by tests of “multiple” intelligence.

More simply stated, the brightest of us aren't as bright we might hope. And definitely not so bright as to rightly claim the prerogatives they have historically claimed.

3 “It is possible that clever people develop a kind of cognitive noblesse oblige; they kind of know they have won the lottery on a valuable trait, but they think it is bad form to acknowledge it.”

See 2. If you're truly smart, you ought to be smart enough to not go prattling on about it. And if you're truly smart and realize that the overwhelming majority of people are truly quite a bit less smart, you ought to be smart enough to understand they may not be smart enough to take your prattling on about it in stride.

I am not arguing that intelligence doesn't exist or in invalid as a concept.

I am arguing that it is quite a bit less operationally important than is here being suggested. Also, I find it pretty odd that in these four posts, the author doesn't do much to address these skepticisms, except perhaps on point 4.

More simply stated, the brightest of us aren't as bright we might hope.By what measure?

And definitely not so bright as to rightly claim the prerogatives they have historically claimed.

What prerogative has ever been "historically claimed" (much less given) to the intelligent people, ever?

If you're truly smart, you ought to be smart enough to not go prattling on about it.

Why not? Why should you be quiet when a bunch of haughty imbecilic bufoons do the "bull in chinashop" routine?

And if you're truly smart and realize that the overwhelming majority of people are truly quite a bit less smart, you ought to be smart enough to understand they may not be smart enough to take your prattling on about it in stride.

May, or may not. Why do I find your "advice" to just grin and bear it, not get the appropriate payoff (social and monetary) for my gifts, while confident imbeciles are laughing all the way to the bank, highly offensive?

I've come across several versions of his "If you're truly smart, you ought to be smart enough to not go prattling on about it. And if you're truly smart and realize that the overwhelming majority of people are truly quite a bit less smart, you ought to be smart enough to understand they may not be smart enough to take your prattling on about it in stride.", and I still fail to truly understand their point?

Is it really smart to pretend not to be smart in order not to offend the majority? In the long term (which, according to a lot of good research, is how the gifted tend to view the world), hiding one's light under a bushel is known not to improve anything for the gifted OR for the beneficiaries of this strategy, as it only ends up securing an unhealthy status quo. Frankly, accepting such a premise is downright irresponsible to humanity!